From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Endurance test report on die-cast versus centri-cast metal bearings for a Bentley III unit.
| Identifier | ExFiles\Box 115\3\ scan0225 | |
| Date | 9th May 1938 | |
| 1020 To By.{R.W. Bailey - Chief Engineer} c. to Fg. c. to Hn.{F. C. Honeyman - Retail orders} c. to RHS. c. to Da.{Bernard Day - Chassis Design} c. to Mx.{John H Maddocks - Chief Proving Officer} c. to DA{Bernard Day - Chassis Design}/JNR.{Charles L. Jenner} Km/Twd{T. W. D???Aeith}1.19/JA.9.5.38. HALLS METAL BEARINGS (AC.9). We have completed a 40 hr. endurance run on a Bentley III unit equipped with the following bearings. Main. Nos. 1.3.5. & 7 die cast to size AC.9 2.4. and 6 centri cast AC.9. Big ends. Nos. 1. 3. and 5 centri cast I.C.7. Nos. 2. 4. and 6 die cast to size A.C.9. These have come through the test in excellent condition, particularly the big end bearings which are almost unmarked. No.5 big end bearing is slightly cracked and is characteristic of centri cast materials as previously tested. We say, therefore that die-cast to size bearings are the most reliable type to be adopted based both on this endurance and previous tests. Regarding the main bearings there is little to choose between the centri-cast and the die cast but again on previous experience we say die-cast, so that all bearings produced will be done in the same manner and the same material namely AC.9. We are confident of the results with big end bearings in die-cast AC.9 being a reliable job in production, but would prefer to have further confirmatory tests in the use of this material as a main bearing owing to the fact that the AC.9 Brinell comes out at 58 - 63 as compared with 47 - 53 on production AC.7 main bearings as used on Bentley II in view of main bearings being a more difficult proposition than big-ends. | ||